The present invention relates to a metal laminate gasket with two seal rings for securely sealing around a hole.
A metal laminate gasket is formed of a plurality of metal plates, wherein sealing means is formed around a hole to be sealed. When high pressure is created inside a hole, such as a cylinder bore, the area around such hole must be tightened strongly with high surface pressure to secure seal around the hole.
In order to seal around such high pressure hole, a seal ring, such as a wire ring, is installed around the hole. In case the wire ring is used, the wire ring may be strongly tightened to provide high surface pressure therearound. However, in case the wire ring formed near the hole is strongly tightened, an area around the hole may deform by the strong tightening pressure.
In such a case, high tightening pressure is not applied near the hole to be sealed. Instead, high tightening pressure is applied at a portion slightly away from the hole to be sealed.
In a gasket, in order to provide moderate surface pressure near a hole to be sealed and high surface pressure at a portion slightly away from the hole, two wire rings may be coaxially provided around the hole, such as shown in Japanese Utility Model Publication (Examined) No. 50-42945.
In the publication, the sizes or diameters of the wire rings, i.e. inner and outer wire rings, are made different to provide different surface pressures at the wire rings. Namely, the diameter of the inner wire ring is made smaller than that of the outer wire ring. Accordingly, two kinds of wire rings with different diameters must always be used, so that it is difficult to change or adjust surface pressures applied around the hole to be sealed.
The present invention has been made to obviate the above drawbacks of the prior art.
Accordingly, one object of the invention is to provide a metal laminate gasket with seal rings, wherein surface pressures at the seal rings can be easily changed or adjusted without changing the seal rings.
Another object of the invention is to provide a metal laminate gasket as stated above, wherein the seal rings with the same or different sizes may be used to seal around a hole.
A further object of the invention is to provide a metal laminate gasket as stated above, wherein the gasket can be easily and economically manufactured.
Further objects and advantages of the invention will be apparent from the following description of the invention.